In 2015 a national heritage building, dating back to the late 1800’s, was renovated using Sika’s reliable products. Having once been owned by a South African Navy sea captain, this majestic old home was subsequently bought in the 1950’s by the Canadian Government and has been used ever since as the main residence for the Canadian High Commissioner in Pretoria. The renovation requirements included concrete repairs, waterproofing and painting with a durable and easily maintained coating system.
In consultation with the High Commissioner’s Material Management Division, Sika specified the best possible products for the project; Cemflex for waterproofing and bonding, Sika MonoTop-615 HB for isolated concrete repairs and Sikagard-550 W Elastic as the main exterior coating for the entire residence and boundary walls.
CPM Projects was awarded the contract and commenced by using Sika MonoTop-615 HB for isolated concrete repairs to the main boundary walls as well as the retaining walls of the main entrance staircase. Sika MonoTop-615 HB is a cementitious, polymer-modified, one-component repair and reprofiling mortar containing silica fume. Designed for thick layer concrete repairs, its adjustable consistency and excellent thixotropic behaviour provides exceptional workability characteristics. Sika MonoTop-615 HB is sprayable by the wet spray method and provides good mechanical strength and good freeze/thaw resistance.
Prior to plastering, Sika’s Cemflex was applied to the retaining walls of the main staircase. An acrylic-based emulsion, Cemflex is watertight, non-toxic, oil resistant and UV stable. When mixed with water and Portland cement it forms an effective waterproofing slurry that is used in conjunction with Cemflex Fabric. When mixed with sand and Portland cement, Cemflex forms a bonding coat for plaster or render.
With the surface of the walls displaying a myriad of fine hairline cracks, internationally approved Sikagard-550 W Elastic was chosen as the best possible solution. This one-component, plasto-elastic coating based on UV-curing acrylic dispersion, provides unsurpassed crack-bridging properties even at temperatures below 0oC. Suitable for protection against ingress, for moisture control and for increasing resistivity, solvent-free Sikagard-550 W Elastic, is water vapour permeable and provides a high diffusion resistance against CO2, thereby reducing the rate of carbonation.
Since Sikagard-550 W Elastic not only effectively covers hairline cracks, but also provides excellent resistance to weathering and ageing with a reduced tendency to dirt pick-up and contamination, the product met all the requirements of this elite residence. This project will undoubtedly be another example of Sika products standing the test of time.